Skip to main content

Local anesthetic toxicity and lipid rescue...



"A Mixed (long- and Medium-chain) Triglyceride Lipid Emulsion Extracts Local Anesthetic from Human Serum In Vitro More Effectively than a Long-chain Emulsion"

Anesthesiology, February 2012




Researchers in the U.K. analyzed the difference between mixed (medium- and long-chain) and long-chain lipid emulsions, for their ability to extract local anesthetic from serum. They concluded that the type of emulsion may make the reversal more effective.


The authors used human drug-free serum and added bupivacaine, ropivacaine, or mepivacaine each at a concentration of 10 µg/ml, or bupivacaine 100 µg/ml at pH 7.4, and, in another experiment, bupivacaine 10 µg at pH 6.9. 20% Intralipid®, which has long-chain triglycerides, or 20% Lipofundin®, which contains a 50-50% mixture of medium- and long-chain triglycerides, was then added at 1, 2, or 4% of total volume. The mean decrease in serum drug concentration was then calculated.

The authors’ in vitro model showed overall that Lipofundin® was significantly better than Intralipid® in extracting the drugs from serum. The relative degree of extraction was bupivacaine > ropivacaine > mepivacaine. This order is consistent with the relative partition constant of each drug. As higher concentrations of either Intralipid® or Lipofundin® were used, the percent decrease of bupivacaine increased and a greater effect was seen with Lipofundin® at each % of lipid. A larger percent decrease in serum bupivacaine was observed after 100 µg/ml bupivacaine compared to 10 µg/ml for both Intralipid® and Lipofundin®, and Lipofundi®n extracted more bupivacaine than Intralipid® at each concentration of either lipid. The effect of pH on sequestering bupivacaine was not significant.

These findings call into question the current advanced cardiac life support guidelines specifying use of a long-chain triglyceride emulsion for lipid rescue, although further in vivo studies that confirm a significant improvement in resuscitation from local anesthetic toxicity with lipofundin are obviously required before drawing any confident conclusions. Also, Lipofundin® is currently commercially unavailable in the United States. Indeed, though the study was performed in the United States, the Lipofundin emulsion that was used was a gift from the manufacturer B. Braun Melsungen AG (Melsungen, Germany)

Labels:

Comments

Post a Comment

Popular posts from this blog

Things to Avoid in Anesthesia for Pregnant with Pulmonary hypertension

Anesthesia for Pregnant woman with Pulmonary Hypertension is a real challenge for anesthesiologist. It is very crucial to remember the pathophysiology of pulmonary hypertension in pregnant women and to avoid some practices that will worsen the cardiac status. 1-Avoid single shot spinal anesthesia. Some authorities consider pulmonary hypertension as absolute contraindication for single shot spinal anesthesia specially in patients with NYHA III ,IV. Spinal anesthesia causes major hemodynamic instability(decrease SVR, decrease VR, decrease in CO) The preferred neuroaxial techniques are (epidural anesthesia and CSE with minimal spinal dose) 2-Avoid PAC. Pulmonary Artery catheters insertion may lead to pulmonary artery rupture or thrombosis. TEE is better cardiac monitor/Arteial line is mandatory. 3-Avoid Nitrous oxide in gas mixture.N2O increase the PVR 4-If MV to be started, avoid High TV and PEEP 5-Avoid Oxytocin Boluses, or rapid administration of Pitocin. Oxytocin causes ...
Post a Comment
Read more

power injectable peripherally inserted central catheters

Clinical experience with power injectable peripherally inserted central catheters in intensive care patients     Introduction In intensive care units (ICU), peripherally inserted central catheters (PICC) may be an alternative option to standard central venous catheters, particularly in patients with coagulation disorders or at high risk for infection. Some limits of PICCs (such as low flow rates) may be overcome by the use of power-injectable catheters . Method We have retrospectively reviewed all the power injectable PICCs inserted in adult and pediatric patients in the ICU during a 12-month period, focusing on the rate of complications at insertion and during maintenance. Results We have collected 89 power injectable PICCs (in adults and in children), both multiple and single lumen. All insertions were successful. There were no major complications at insertion and no episodes of catheter-related blood stream infection. Non-infective complications ...
1 comment
Read more

Lumbar and thoracic epidural in Pediatrics-Technical aspect

The midline approach is most commonly used. The ligamentum   flavum is considerably thinner and less dense in infants than in older children and adults. This makes recognition of engagement in the ligament more difficult and requires both extra care and slower, more deliberate passage of the needle to avoid subarachnoid puncture. The angle of approach to the epidural space is slightly more perpendicular to the plane of the back than in older children and adults, owing to the orientation of the spinous   processes in infants and small children. The loss of resistance technique should be used, but only with saline, not air. There are several reports of venous air embolism in infants and children when air was used to test for loss of resistance Use a short (5 cm) 18-gauge Tuohy needle and a 20- or 21-gauge catheter in infants and children. Epidural kits specifically for infants and children are available Maximum of 0.4 mg/kg/hr of bupivacaine after the initial block is estab...
Post a Comment
Read more